Autoimmune Encephalitis in Pregnancy: A Case Report.

Autoimmune encephalitis is a rare and heterogeneous group of inflammatory disorders of the central nervous system, occasionally occurring during pregnancy and posing diagnostic and therapeutic challenges. Pregnancy-related physiological changes and the need to avoid potentially teratogenic treatments often delay diagnosis and intervention. We report the case of a 27-week primigravida who presented with acute mental status deterioration. On admission, she was hemodynamically stable but exhibited a Glasgow Coma Scale (GCS) score of 10/15. Fetal bradycardia prompted an emergency cesarean section. Neuroimaging revealed mild temporal and parietal lobe edema, while cerebrospinal fluid analysis showed borderline lymphocytic pleocytosis without infectious or autoimmune antibodies. Despite the absence of specific immunomodulatory therapy, the patient improved gradually with supportive and antiepileptic treatment (levetiracetam and phenytoin) and was discharged in good condition after two weeks. Compared with published reports, this case was atypical due to its onset in the late second trimester, minimal neuroimaging findings, and negative antibody profile. A recent COVID-19 infection preceding symptom onset was also unique among documented cases. The favorable outcome without immunotherapy suggests that some seronegative, mild presentations may follow a self-limited course. Our case adds to the growing evidence that autoimmune encephalitis in pregnancy can present with atypical and antibody-negative features that mimic other obstetric complications, such as eclampsia. Prompt multidisciplinary assessment, careful exclusion of alternative diagnoses, and close neurological follow-up are critical to optimizing maternal and fetal outcomes.